This invention relates to armatures for conducting very large current between parallel rails of an electromagnetic launcher and, more particularly, to such armatures which employ multiple conducting fibers to conduct current between the launcher rails.
In the electromagnetic propulsion of projectiles, a very large DC current which may be on the order of 1 million amperes, is injected into the breech end of a pair of conductive parallel rails. A sliding conductive armature serves to conduct current between the rails and is accelerated by the interaction of a magnetic field generated by current flowing in the rails and the current passing through the armature. The armature is mechanically linked to a payload, thus providing the payload acceleration necessary for a launch.
Although metal fiber armatures have been successfully used to accelerate projectiles, some arcing and rail damage has resulted from poor mechanical behavior of the fibers. U.S. Pat. No. 4,457,205, issued July 3, 1984 to Ross discloses multifiber armatures for electromagnetic launchers and is hereby incorporated by reference.
One embodiment of the Ross armature includes fibers which are swept back from a central band that lies perpendicular to the launcher rail surfaces. Such a design may not provide sufficient control over the ends of the fibers. A second embodiment of the Ross armature includes short fibers attached to a chevron structure. That embodiment has limited practicality because of the difficulty of joining the metal fibers to the solid metal chevron.